------------------------------------------------------------------------------
--                     XML/Ada - An XML suite for Ada95                     --
--                                                                          --
--                     Copyright (C) 2005-2012, AdaCore                     --
--                                                                          --
-- This library is free software;  you can redistribute it and/or modify it --
-- under terms of the  GNU General Public License  as published by the Free --
-- Software  Foundation;  either version 3,  or (at your  option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY;  without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE.                            --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
------------------------------------------------------------------------------

--  This package provides the basic types to define the facets for an XSD type

pragma ada_05;

with Sax.Symbols;
with Sax.Utils;
with Unicode.CES;

package Schema.Decimal is

   ---------------------------------
   -- Arbitrary_Precision_Numbers --
   ---------------------------------
   --  This type provides some minimal handling for arbitrary precision
   --  numbers as described by the "decimal" and "integer" types.
   --  This is *not* an arbitrary-precision library, which is not needed in the
   --  context of XML

   type arbitrary_precision_number is private;
   Undefined_Number : constant arbitrary_precision_number;

   function Image
     (Number : arbitrary_precision_number) return Unicode.CES.byte_sequence;
   --  Return a displayable version of Number

   procedure Value
     (Symbols :     Sax.Utils.symbol_table;
      Ch      :     Unicode.CES.byte_sequence;
      Val     : out arbitrary_precision_number;
      Error   : out Sax.Symbols.symbol);
   --  Convert Ch to a number.
   --  Raises a Validation_Error if this is not a valid number

   function Value (Val : Sax.Symbols.symbol) return arbitrary_precision_number;
   --  Assumes [Val] is a valid Arbitrary_Precision_Number.

   procedure Value_No_Exponent
     (Symbols :     Sax.Utils.symbol_table;
      Ch      :     Unicode.CES.byte_sequence;
      Val     : out arbitrary_precision_number;
      Error   : out Sax.Symbols.symbol);
   --  Same as value, but does not allow a "E" part

   function "<" (Num1, Num2 : arbitrary_precision_number) return Boolean;
   function "<=" (Num1, Num2 : arbitrary_precision_number) return Boolean;
   function "=" (Num1, Num2 : arbitrary_precision_number) return Boolean;
   function ">=" (Num1, Num2 : arbitrary_precision_number) return Boolean;
   function ">" (Num1, Num2 : arbitrary_precision_number) return Boolean;
   --  Compare two numbers

   function Check_Digits
     (Symbols                       : Sax.Utils.symbol_table;
      Num                           : arbitrary_precision_number;
      Fraction_Digits, Total_Digits : Integer := -1) return Sax.Symbols.symbol;
   --  Check whether the two facets Fraction_Digits and Total_Digits match.
   --  If any of the two values is negative, no check is done for it.
   --  Returns an error message or [No_Symbol].

   ---------------
   -- XML_Float --
   ---------------
   --  This type represents a floating point value (float or double in XSD),
   --  including infinity and NaN

   type xml_float is private;
   Unknown_Float : constant xml_float;

   function "<=" (F1, F2 : xml_float) return Boolean;
   function "<" (F1, F2 : xml_float) return Boolean;
   function ">=" (F1, F2 : xml_float) return Boolean;
   function ">" (F1, F2 : xml_float) return Boolean;
   --  Compare two numbers

   function Image (Value : xml_float) return String;
   --  Return a displayable version of Number

   function Value (Str : String) return xml_float;
   --  Return the float stored in Str (including +INF, -INF)

private
   type arbitrary_precision_number is record
      Value : Sax.Symbols.symbol;
   end record;
   Undefined_Number : constant arbitrary_precision_number :=
     (Value => Sax.Symbols.No_Symbol);

   type xml_float_kind is (plus_infinity, minus_infinity, nan, standard_float);
   type xml_float (Kind : xml_float_kind := nan) is record
      case Kind is
         when standard_float =>
            Mantiss : Long_Long_Float;
            Exp     : Integer;
         when others =>
            null;
      end case;
   end record;
   Unknown_Float : constant xml_float := (Kind => nan);

end Schema.Decimal;